Answer:
pH: 11
pOH: 3
Explanation:
NaOH is a strong base which means that it dissociates completely in water. It will break apart into Na⁺ and OH⁻ ions.
NaOH ⇒ Na⁺ + OH⁻
Because NaOH dissociates completely into its respective ions in water, the moles of NaOH is equal to the moles of hydroxide ions. So, [OH⁻] = 0.001 M.
Now to find the pOH, use the formula pOH = -log[OH⁻].
pOH = -log[OH⁻]
= -log(0.001)
= 3
The pOH of the solution is 3.
To find the pH, subtract the pOH from 14 since pH + pOH = 14.
14 - 3 = 11
The pH of the solution is 11.
Hope that helps.
The temperature of a sample of liquid water changes from 50°C to 30°C. Which statement best explains the change
that must happen at the molecular level?
ОООО
The molecules move more quickly and their average kinetic energy increases.
The molecules move more slowly and their average kinetic energy decreases.
The molecules move more quickly and their average kinetic energy decreases.
The molecules move more slowly and their average kinetic energy increases.
Answer:
The molecules move more slowly and their average kinetic energy decreases
Explanation:
The increased temperature meant that the atoms in liquid had a greater average energy of motion so as the temperature decreases the reaction would be inverse.
The branch of science which deals with the chemicals bond is called chemistry.
The correct option is B.
The energy which is produced by the motion of the particles is called kinetic energy. Temperature increases the motion of the particles. So, the kinetic energy increases when the temperature rises.
According to the question, the temperature of the water decreases therefore the kinetic energy decreases.
Hence, the correct option is B that is the molecules move more slowly and their average kinetic energy decreases.
For more information, refer to the link:-
https://brainly.com/question/25026730
A container initially holds 5.67 x 10^10-2 mol of propane and has a volume of V1. The volume of the container was increased by adding an additional 2.95 x 10^-2 mol of propane to the container, so that the container has a final volume of 1.93 L. If the temperature and pressure are constant, what was the initial volume of the container ,V1?
Answer:
The initial volume of the container was 1.27L
Explanation:
Avogadro's law states that under the same pressure and temperature, equal moles of gases occupies equal volume. The equation is:
V₁n₂ = V₂n₁
Where V is volume and n moles of 1, initial state and 2, final state.
In the problem, initial moles are 5.67x10⁻², final moles after the addition are:
5.67x10⁻² + 2.95x10⁻² = 8.62x10⁻² moles
And, after the addition, the volume is 1.93L.
Replacing in Avogadro's law:
V₁×8.62x10⁻² moles = 1.93L×5.67x10⁻² moles
V₁ = 1.27L
The initial volume of the container was 1.27LIf 50.0cm3of a saturated solution of KNO3at 40oC contained 5.05g of the salt. What is the solubility of the salt at 40oC? [KNO3=101].
Answer:
The solubility of KNO₃ at 40° C is 1 mol/dm³
Explanation:
The solubility of a substance is the number of moles of that substance (solute) contained in a unit volume of solvent at that particular temperature.
Now, Solubility = n/V where n = number of moles of KNO₃ and V = volume of saturated solution = 50.0 cm³ = 0.05 dm³
n = m/M where m = mass of KNO₃ = 5.05 g and M = molar mass of KNO₃ = 101 g/mol
n = 5.05 g/101 g/mol = 0.05 mol
Solubility = n/V
= 0.05 mol/0.05 dm³
= 1 mol/dm³
So, the solubility of KNO₃ at 40° C is 1 mol/dm³
When N2gas is passed through water at 293k.how many moles of N2 dissolve in 1litre water
Answer: 7 milimoles of [tex]N_2[/tex] dissolve in 1 litre water.
Explanation:
Given: [tex]N_2[/tex] gas is passed through water at 293K.
Assumption :[tex]N_2[/tex] exerts a partial pressure of 0.987 bar.
Take : Henry's constant [tex]p_N_2[/tex] = 76.8 Kbar
[tex]K_H=76800[/tex]
To find : Number of moles of [tex]N_2[/tex] gas dissolve in 1 litre water.
According to Henry's law,
[tex]p_N_2=K_HX_{N_2}[/tex]
[tex]\Rightarrow\ 0.987=76800X_{N_2}[/tex]
[tex]\Rightarrow\ X_{N_2}=\dfrac{0.987}{76800}=0.0000128515625\approx1.29\times10^{-5}[/tex]
moles in 1 liter of water = [tex]\dfrac{1000}{18}=55.56\ [\text{Molar mass of }H_2O=18\ g][/tex]
Let n= moles of nitrogen
Total moles = 55.56+n
So,
[tex]X_{N_2}=\dfrac{n}{55.56+n}=1.29\times10^{-5}\\\\\Rightarrow\ 55.56\times1.29\times10^{-5}+1.29\times10^5n=n\\\\\Rightarrow\ n- 1.29\times10^5n=0.000714033\\\\\Rightarrow\ 0.999987n=0.000714033\\\\\Rightarrow\ n\approx7\text{ milimoles}[/tex]
Hence, 7 milimoles of [tex]N_2[/tex] dissolve in 1 litre water.
why ammonium is not a molecular ion
Answer:
See below
Explanation:
Ammonium [tex](NH_{4}^+)[/tex] is not a molecular ion because it is just a poly-atomic ion. A molecular ion has a "negative or positive charge" as a whole but the positive charge on here is not on the whole. So, it is a poly-atomic ion and not molecular ion.
For a system, H2(g) + I2(g) ⇌ 2 HI(g), Kc = 62.9 at 750 K. 2.80 moles of HI were placed in a 10.0-liter container, brought up to 750 K, and allowed to come to equilibrium. Which situation described below is true, at equilibrium?
a. [HI] = 2 × [H2]
b. [HI] = [H2]
c. [HI] < [H2]
d. [HI] > [H2]
e. [H2] > [I2]
Answer:
d. [HI] > [H2]
Explanation:
The explanation at equilibrium is shown below:-
Data provided [tex]H_2(g) + I(g) \rightleftharpoons 2HI_(g)[/tex]
Initial concentration - - [tex]\frac{2.80}{10}[/tex] = 0.280 M
At equilibrium x x 0.280 - 2x
[tex]K_c = \frac{(HI)^2}{(H_2)(I_2)} = 62.9[/tex]
[tex]= \frac{(0.280 - 2x)^2}{x^2} = 62.9\\\\4x^2 - 1.12x + 0.0784 = 62.9x^2[/tex]
After solve the above equation we will get
x = 0.0282 M
Therefore at equilibrium
[tex][H_2] = [I_2] = x = 0.0282M\\\\[/tex]
[tex][HI] = 0.280 - 2x = 0.2236 M[/tex]
Hence, the correct option is d.
Select the correct answer.
What is the reason for heat transfer from one substance to another
Answer:
Difference in temperature.
Explanation:
Conduction is the movement of heat energy through a substance or from one substance to another by direct contact of atoms and molecules. Heat moves directly from one molecule to another. The heat energy speeds up the movement of the atoms and they collide with other molecules setting them into faster motion.
Q2.
For the reaction given, how many litres of carbon dioxide gas will be formed by the reaction of 400
litres of oxygen with sufficient pentene (CH..)? The reaction takes place at 125°C and 10.5 atm.
2 C5H10(1) + 15 O2(g) →10 CO2(g) + 10 H20 (8)
Answer:
266 liters Carbon iv oxide will be formed
Explanation:
The first thing we need to do here is to calculate the number of moles of oxygen reacted.
This can be calculated using the ideal gas equation;
Mathematically;
PV = nRT
From the question;
P = pressure = 10.5 atm
V = volume = 400 liters
n = number of moles = ?
T = temperature = 125 + 273 = 398K
R = molar gas constant = 0.0821 L•atm•K^-1•mol^-1
Substituting these values, we have ;
n = PV/RT
n = (10.25 * 400)/(398 * 0.0821) = 125 moles
From the question;
15 moles oxygen gave 10 moles CO2
125 moles oxygen will give x moles CO2
x = (125 * 10)/15 = 83 moles
Now, we want to know the volume of CO2, present in 83 moles using the given reaction conditions.
Mathematically;
PV = nRT
V = nRT/P
= (83 * 0.0821 * 398)/10.25 = 265.65 which is approximately 266 Liters
using equation of reaction mention 4 methods of preparation of hydrogen
Explanation:
1. Displacement of hydrogen from water by using metal
2. Electrolysis of water using the apparatus known as the HOFMAN VOLTAMETER
3. Cracking of petroleum
4. Action of steam on hot coke
The structures found in a living cell can be compared to the parts of a factory that produces cars. Which part of the factory is most similar to the nucleus of a living cell? *
The computers that help control the machines in the factory
Which type of river is similar to a mature river, but flows more slowly so has less power to change the landscape? Select one: a. Youthful River b. Mature River c. Old Age River
Answer:
The correct option is;
C. Old Age River
Explanation:
Among the three stages of the development of a river, which are the youthful, mature, and old age stages, the old age river is least dynamic
The water is very slow moving with a low gradient and lesser erosive power to alter the landscape which results in the appearance of flood planes
Examples of old age rivers include, lower Ganges, lower Nile, Indus, and Yellow rivers
Old age rivers are characterized by a broad shape, with a wide flood plane, a very gentle gradient and the water current is low.
Answer:c
Explanation:
old age river
when humans burn fossil fuels, most of the the carbon quickly enters the atmosphere as carbon dioxide in the atmosphere in the process called
•transpiration
•combustion
•decomposition
•photosynthesis
Which metal will react spontaneously with Cu2+ (aq) at 25°C?
Hg
Mg
Ag
Au
Answer:
Mg
Explanation:
The standard reduction potentials are
E°/V
Au³⁺(aq ) + 3e⁻ ⟶ Au(s); 1.42
Hg²⁺(aq) + 2e⁻ ⟶ Hg(l); 0.85
Ag⁺(aq) + e⁻ ⟶ Ag(s); 0.80
Cu²⁺(aq) + 2e⁻ ⟶ Cu(s); 0.34
Mg2+(aq) + 2e- ⟶ Mg(s); -2.38
The more negative the standard reduction potential, the stronger the metal is as a reducing agent.
Mg is the only metal with a standard reduction potential lower than that of Cu, so
Only Mg will react spontaneously with Cu²⁺.
Answer:
B. Mg
Explanation:
Which formula contains a metal and a nonmetal? SO2 MgO CO H2O
Answer:
MgO
Explanation:
Mg, which is magnesium, is considered a metal, when paired with Oxygen, which is a gas, it creates magnesium oxide, and the formula itself is a pairing of a metal with a nonmetal
Answer:
[tex]\boxed{MgO}[/tex]
Explanation:
Metals are red, nonmetals are blue, and metalloids are yellow in the attached file.
Using this table, you can see that Mg is a metal and O is a nonmetal, which fits the question criteria.
Hope this helps!
Which event is most likely occurring? diffusion because particles move from regions of high concentration to regions of low concentration diffusion because particles move from regions of low concentration to regions of high concentration effusion because there is a movement of a gas through a small opening into a larger volume effusion because there is a movement of a gas through a large opening into a smaller volume
Answer: c
Explanation: effusion because there is a movement of a gas through a small opening into a larger volume
someone help me please....
Answer:
i- In beaker A, sodium chloride will dissolve with water.
and in beaker B, there will be no reaction.
ii- sodium chloride is soluble in water, while sand is insoluble.
iii- The reaction can be increased by adding more sodium chloride to the beaker.
iv- The sodium chloride will no longer dissolve in the water.
A civil engineer chooses to use wooden beams because they will sag before
they break. This is an example of:
A. using a material for multiple applications.
B. choosing a material that will show warning before it fails.
C. using composite materials that combine strengths.
D. using design techniques that increase efficiency and reduce
costs.
Answer:
B. choosing a material that will show warning before it fails.
Explanation:
Answer:
APEX
Explanation:
B
Why does fumaric acid have a higher boiling point than maleic acid, even though they both can form hydrogen bonds?
Answer:.
Explanation:
The client had the following for dinner: 8 ounces of pears 8 ounces of ginger ale 8 ounces of peaches 1 chicken tenders meal 1 popsicle (40 mL) 8 ounces of liquid meal supplement (i.e. Ensure®) What is the client's total intake?
Answer:
Client's total intake = 32 ounce of liquid meal supplement
Explanation:
Given:
Meal take
8 ounces of pears
8 ounces of ginger
8 ounces of peaches
liquid meal supplement = 8 ounces
Find:
Client's total intake.
Computation:
Client's total intake = 8 ounces of pears + 8 ounces of ginger + 8 ounces of peaches + 8 ounces liquid meal supplement
Client's total intake = 32 ounce of liquid meal supplement
How will freezing the juice affect its mass?
Answer:
Mass increases since its going from liquid to solid.
Explanation:
someone plz plz answer this hurry plz it
Answer:
b
Explanation:
A 25.0 mL sample of a solution of an unknown compound is titrated with a 0.115 M NaOH solution. The titration curve above was obtained with pH at equivalence point of around 8. The unknown compound is ________.
Answer:
Weak acid
Explanation:
A titration curve is a graphical description of the change in pH of the solution in the conical flask as the reagent is added from the burette. A titration curve can be plotted for the different kinds of acid and base titrations. The volume of the titrant is always plotted as the independent variable and the pH of the solution as the dependent variable. The equivalence point is read off from the titration curve. A titration curve is very important because it shows the pH at various points during the titration.
A weak acid/strong base titration leads to an equivalence point above 7. From the question, we were told that the pH at equivalence point lies around 8. Hence the unknown substance must be a weak acid.
Which of the following may suggest a catalyst has been used in a reaction, given the energy diagram for the same reaction without a catalyst?
Why are the oxidation and reduction half-reactions separated in an
electrochemical cell?
Answer:
Electrochemical cells typically consist of two half-cells. The half-cells separate the oxidation half-reaction from the reduction half-reaction and make it possible for current to flow through an external wire.
Explanation:
Two oxides of lead were separately reduced to metallic lead by heating in a current of
i) Mass of yellow oxide taken=3.45g
ii) Mass of brown oxide taken=1.227g
Loss in mass during reduction=16g
Show that the above data illustrate the law of multiple proportions.
Answer:
HeyA ❤
Let us consider the mass of oxygen as 1 g.
Mass of lead obtained from yellow oxide = 3.45 g – 0.24 g = 3.21 g
Mass of oxygen = 0.24 g
The mass of lead that combines with 0.24 g of oxygen = 3.21 g
Therefore, mass of lead that combines with 1 g of oxygen = 3.21/ 0.24 = 13.4 g
Mass of lead obtained from brown oxide = 1.227 g – 0.16 g = 1.067
Mass of oxygen = 0.16g
The mass of lead that combines with 0.16 g of oxygen = 1.067 g
Therefore, mass of lead that combines with 1 g of oxygen = 1.067/ 0.16 = 6.66 g
Now, ratio of masses of lead which combines with a fixed mass of oxygen = 13.4 : 6.66
= 2 :1
Thus, masses of lead which combine with the fixed mass of oxygen are in the ratio of (2:1) i.e. small whole numbers.
Hence, the law of multiple proportions is illustrated.
Follow meehhhh Piper ❤
Who is john Dalton ?
Answer:
He is a English chemist physicist and meteorologist. He is best known for the atomic theory
Answer:
John Dalton was a scientist.
Explanation:
A climber is attached to a vertical rope that has a tension of 785 N. If the
climber has a mass of 85 kg, what is the net force on the climber?
O A. 48 N up
OB. 542 N up
O C. 700 N down
O D. 48 N down
SUBMIT
Answer:
D. 48 N down
Explanation:
Given that:
Mass of climber = 85 kg, Tension on rope = 785 N, acceleration due to gravity = 9.8 m/s²
To calculate the net force on the climber, we need to first calculate the weight of the climber. Since the climber is affected by the earth gravity, the weight of the climber is the product of his mass and the acceleration due to gravity, therefore:
Weight = mass × acceleration due to gravity = 85 kg × 9.8 m/s² = 833 N
The weight of the climber is acting downwards while tension on the rope is acting upwards, therefore:
Net force on the climber = 785 N - 833 N = - 48 N
This means that the net force on the climber is 48 N downwards
Answer:
48 N down
Explanation:
Ayepecks
The volume of a sample of pure HCl gas was 221 mL at 20°C and 111 mmHg. It was completely dissolved in about 50 mL of water and titrated with an NaOH solution; 18.7 mL of the NaOH solution was required to neutralize the HCl. Calculate the molarity of the NaOH solution.
Answer:
[tex]molarity =6.9\times 10^{-3}\ M\\[/tex]
Explanation:
We know that , the reaction of HCl and NaOH is given as follows
[tex]NaOH+HCl=NaCl +H_2O[/tex]
Given that
Pressure = 111 mm Hg
[tex]P=111\times 13.6\times 10^{-3}\times 9.81\times 1000=14.809\ kPa[/tex]
Temperature = 20°C
T=20+273=293 K
Volume= 221 m L
V=0.221 L
Number of moles of HCl is given as follows
[tex]n=\dfrac{P\times V}{R\times T}\\n=\dfrac{0.148\times 0.221}{0.821\times 293}=1.3\times 10^{-4}\ moles[/tex]
From the above reaction we can say that
Number of moles of HCl=Number of moles of NaOH
Volume of NaoH is given as follows
V=18.7 = 0.0187 L
Therefore molarity
[tex]molarity =\dfrac{n}{V_{NaOH}}\\molarity =\dfrac{1.3\times 10^{-4}}{0.0187}=6.9\times 10^{-3}\ M\\molarity =6.9\times 10^{-3}\ M\\[/tex]
What percentage of the total incoming radiation to the Earth reaches the ground? 20 30 40 70
Answer: 22.5 percent of incoming solar radiation goes directly to the surface of the Earth and is absorbed.
Explanation: Transfer of radiation through a planet's atmosphere. A planet and its atmosphere, in our solar system, can radiate back to space only as much energy as it absorbs from incoming solar radiation.
Answer:
Explanation:
I have the notes
"Only about 40 percent actually reaches the surface of the earth"
"our atmosphere and clouds reflect bout 40 percent of incoming solar radiation back into outer space"
"The remaining 60 percent is responsible for warming the earth"
"About 20 percent of this radiation is absorbed directly by the atmosphere"
Acetic acid (CH3COOH) is a weak acid that partially dissociates in water. Given the reaction CH3COOH(aq) ↔ CH3COO−(aq) + H+(aq) and Kc = 1.8 x 10−5, if the concentration of the acetic acid is 0.016 M and the concentration of the acetate ion is 0.92 M, what is the [H+]?
Answer:
The correct answer is: 1.035 x 10⁻³ M
Explanation:
The dissociation equilibrium for acetic acid (CH₃COOH) is the following:
CH₃COOH(aq) ↔ CH₃COO⁻(aq) + H⁺(aq) Kc = 1.8 x 10⁻⁵
The expression for the equilibrium constant (Kc) is the ratio of concentrations of products over reactants. The products are acetate ion (CH₃COO⁻) and hydrogen ion (H⁺) while the reactant is acetic acid (CH₃COOH):
[tex]Kc=\frac{[CH_{3} COO^{-} ][H^{+} ]}{[CH_{3} COOH]}= 1.8 x 10^{-5}[/tex]
Given: [CH₃COOH]= 0.016 M and [CH₃COO⁻]= 0.92 M, we replace the concentrations in the equilibrium expression and we calculate [H⁺]:
[tex]\frac{(0.016 M)[H^{+} ]}{(0.92M)}= 1.8 x 10^{-5}[/tex]
⇒[H⁺]= (1.8 x 10⁻⁵)(0.92 M)/(0.016 M)= 1.035 x 10⁻³ M